How do urban legends retain their vitality?  Ignorant people pass them along as fact.  Unfortunately, sometimes that includes the national media, as it does today in the Washington Post.  In a report on Barack Obama’s get-tough policy with Mexico, reporter Spencer Hsu repeats the canard that 90% of the guns seized by Mexican authorities come from the US:

The Obama administration accelerated what is normally a year-long effort to add names to the banned list. The government did not identify assets held by the three cartels, but authorities have estimated that $19 billion to $39 billion in drug proceeds flows south each year from the United States.

The financial sanctions provide an additional tool against the organizations, whose drug and gun trafficking has proved exceedingly difficult to curtail. Mexico, for example, has seized more than 35,000 firearms from narco-traffickers since December 2006, and both governments say 90 percent of the weapons originated in the United States.

The effort to curb the southbound flow of what some have called an “iron river of guns” has faced heavy obstacles, including limited resources, relatively open access to firearms and political opposition to tighter gun regulation.

Apparently, it’s not enough to skip checking the stats for Hsu.  He has to wax poetic about “an iron river of guns,” which in the end makes him and his patented Layers of Fact-Checkers and Editors look all the more foolish.  Because, as we know and the ATF has already admitted, that statistic is just plain false.

The ATF correctly states that of the guns that can be successfully traced by the ATF or FBI from the guns sent to them by Mexican authorities, about 90% have origins in the US.  However, Mexico doesn’t send all of the guns that they capture to the US for tracing; only about a third of them get sent here.  Of that third, roughly half can’t be traced at all, thanks to efforts to strip the weapons of registration markings.  With the other half, about nine of ten can be traced to the US, which works out to about 17% of all weapons seized by Mexican officials.

Even Hsu’s data should have given him a clue.  With 35,000 weapons confiscated, a 90% figure should mean the US identified 31,500 weapons as originating in the US.  However, during that time, only 5,114 of those weapons got traced back to the US, or about 17%, give or take.  The rest of the weapons originate in Russia, China, Central and South America — and from discharged veterans and deserter from the Mexican Army, who keep their weapons and then sell them on the black market.

This is the kind of information that might be handy to WaPo readers: accurate and factual.  Perhaps both governments trot out that nonsense, but shouldn’t newspapers exist to test government claims?  However, when one knows what the real numbers are, one can’t write about an “iron river of guns.”  Maybe Hsu should stick to poetry.